The invention particularly relates to gear systems, and more particularly to gear mechanism of the type utilized, for instance, to mechanically drive the input shaft of a gasoline station computer to indicate the total price of the liquid dispensed from the gasoline pump. Formerly, when the price per gallon involved two digit numbers, such computers registered "total price" directly, but with the advent of price increases, which have raised the price per gallon over one dollar, gasoline pump computers of the mechanical variety, have not directly registered the correct amount which the customer owes. Rather, it has been customary for the service station attendant to set the pump computer at one-half the price per gallon and then double the amount shown on the register to arrive at the proper figure. To obviate this problem, we have developed a gear adaptor to fit over the existing drive gear and provide twice the number of driving teeth as previously. The gear adaptor is molded of a self-lubricating plastic, such as polyurethane, and enables a price variator to be set at the price per half gallon to compute and register the full price per gallon.
While worm wheel wear rings, having internal teeth and external teeth, such as, for example described in U.S. Pat. No. 4,077,274, have previously been suggested for use in excessive "wear" situations, the novel concepts disclosed by the present invention have never, to our knowledge, previously been utilized to achieve the results sought by the present inventors.
One of the prime objects of the present invention is to provide a direct read-out adaptor system which can be very economically manufactured and marketed.
Another object of the invention is to provide a system of the character described which permits the service station owner to adapt the present mechanical computer in a reliable and rapid manner, without incurring the considerable costs of changing the computer.